Energy absorption systems of vehicles, particularly bumper systems with deformable brackets that can absorb energy to decrease impact forces during a collision, promote enhanced safety during operation of the vehicle by mitigating damage to foreign objects that collide with the vehicle. Thin walled metal plates (i.e., steel, aluminum), expanded foam, and other plastic absorbers including ribbed structures, thermo-formed and blow molded parts yield energy absorption to lessen collision impact forces while maintaining structural rigidity of the bumper system. Such methods of forming bracket parts can lead to easily and unevenly deforming parts, causing peaks in collision forces experienced by the foreign object as easily deformable parts are crushed against nondeforming parts such as a bumper beam.
A need was identified for a vehicle energy absorption system having a force deflection curve resembling a more efficient “square wave” that increases a reaction force immediately after an initial buckling phase of the deformable parts.